This nonprovisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 2002-111090 and 2003-103571 filed in JAPAN on Apr. 12, 2002 and Apr, 8, 2003, which is (are) herein incorporated by reference.
1. Field of the Invention
The present invention relates to an arrangement of a maintenance mechanism designed for an ink-jet type printer that produces a printed record by applying ink droplets to a recording medium.
2. Description of the Related Art
In general, an ink-jet printer has the following three operational modes: (1) a capping operation mode; (2) a cleaning operation mode; and (3) a printing operation mode. The capping operation mode serves to prevent drying of ink in a printing head, and to protect its nozzle. The cleaning operation mode is-composed of a wiping operation for wiping and cleaning the nozzle to remove residual ink and foreign substances deposited onto the nozzle surface of the printing head, and a spitting operation for discharging ink. The printing operation mode serves to perform an ordinary printing operation.
Of the three operational modes, the former two are related to maintenance required for operating the printer properly. Commonly, a maintenance station incorporating a maintenance mechanism for achieving proper maintenance is arranged in a position outside the printing region so as not to disturb the printing operation. For example, Japanese Unexamined Patent Publication JP-A 2000-233517 (2000) discloses one example of a maintenance station as shown in FIGS. 9, 10, and 11. In this example, the maintenance station is arranged in a left-hand position outside the printing region.
With reference to these drawings, the above-mentioned operational modes will be described. At first, in FIG. 9, a maintenance station 36 is positioned at the left end defined as one end of the main scanning direction in synchronism with a carriage 32. The carriage 32 is guided by a carriage shaft 35 which is horizontally suspended by a main frame 31. A side wall A of a slide case abuts against the inner side of the left-hand side wall defined as one end side wall of the main scanning direction of the main frame 31. In this positional arrangement, the maintenance station 36 is held at the highest position (top dead center) by the action of a sliding projection C which is loosely and slidably fitted in a slanted cam groove B formed in a base portion 39 of the printer. Mounted in the maintenance station 36 are a cap 37a and a cap 37b for hermetically sealing nozzle portions (their positions are indicated by symbols ▾) of two printing heads 33 and 34.
On the other hand, two wipers 38a and 38b mounted in the maintenance station 36 are located on the right-hand sides defined as other ends of the main scanning direction of the printing heads 33 and 34, respectively. Since these wipers 38a and 38b are kept out of contact with the nozzle surface, the wiping operation is not effected in this state. In the ink-jet printer, this state is normally regarded as a so-called standby state for awaiting printing instructions, that is, the power is turned off, or no printing operation is being carried out.
Next, in FIG. 10, the maintenance station 36 is moved slightly toward the lower right defined as the one lower end along the main scanning direction in accompaniment with the carriage 32 which moves rightward, namely, the other end along the main scanning direction. The sliding projection C is locked, in the midpoint of the cam groove B, by a non-illustrated locking mechanism. In this state, the maintenance station 36 is moved slightly downward away from the printing heads 33 and 34, and the two caps 37a and 37b are kept away from the nozzle portions of the two printing heads 33 and 34, respectively. However, the interval between the maintenance station 36 and the printing head 33 and 34 is set to be shorter than the height of the wiper 38a and 38b. 
Therefore, the front end of the wiper 38a, 38b exceeds the height of the nozzle surface of the printing head 33 and 34 in the free state. Since the carriage 32 carrying the two printing heads 33 and 34 is being moved toward the printing region, during this time, the wipers 38a and 38b are flexibly brought into sliding contact with the nozzle surfaces of the moving printing heads 33 and 34, thereby achieving the wiping operation.
Moreover, in the state shown in FIG. 10, in addition to the wiping operation, the operation for discharging ink (spitting operation) is carried out to remove residual ink deposited onto the nozzle surfaces of the printing heads 33 and 34. That is, as shown in the figure, while the nozzle portion of the printing head 33 and 34 is located in the region between the wiper 38a and 38b and the cap 37a and 37b, ink is discharged by driving the printing head 33 and 34. The ink thus discharged is stored, as waste ink, in a non-illustrated discharge pot (waste ink collecting bath) arranged on the bottom surface of the maintenance station 36.
In FIG. 11, the sliding projection C is unlocked, and moved toward the right end defined as the other end along the main scanning direction of the cam groove B in accompaniment with the carriage 32 which moves rightward, namely, to the other end along the main scanning direction. The maintenance station 36 is held at the lowest position (bottom dead center), and moved downward further away from the printing heads 33 and 34, and the two caps 37a and 37b are entirely kept away from the nozzle portions of the printing heads 33 and 34, respectively. The front ends of the wipers 38a and 38b are also moved away from the nozzle surfaces of the printing heads 33 and 34, respectively. The carriage 32 is moved reciprocally along the main scanning direction. Thereupon, the printer is brought into the printing operation mode, whereby printing is performed on a recording medium in accordance with printing signals.
However, the above stated conventional example has the following disadvantages. Integrating the maintenance station 36 in one-side position (left-hand side position defined as the one end along the main scanning direction) outside the printing region gives rise to a problem of the structure being complicated, as well as a problem of the structure occupying an unduly large area. Resultantly, the apparatus main body cannot be made compact as a whole. Meanwhile, an attempt to downsize the maintenance station 36 makes it impossible to secure a sufficient volumetric capacity in the waste ink collecting bath.
Moreover, in terms of structural design, the caps 37a and 37b and the wipers 38a and 38b cannot be moved upwardly and downwardly without moving the maintenance station 36 slidingly to both main scanning directions, namely, from side to side. Thus, extra space is required in the direction of the width of the apparatus main body (indicated by reference symbol L2 in FIG. 11). Further, being built as a 2-pen type ink-jet printer, the printing head 33 and 34; the cap 37a and 37b; the wiper 38a and 38b; and the waste ink collecting bath each need to be arranged pairwise. Integrating such a large number of components in one position results in the maintenance mechanism as a whole being complicated, and the size of the apparatus being increased. This makes miniaturization difficult.